Field
Exemplary embodiments of the present disclosure relate to ceramic compositions and to composite ceramic compositions comprising aluminum magnesium titanate, cordierite, and mullite having a high cordierite to mullite ratio.
Discussion of the Background
Cordierite and aluminum titanate-based honeycombs have been widely used for a variety of applications, such as catalytic substrates and filters for diesel and gasoline particulate emission. Recently, filter material families have been extended to include cordierite-mullite-aluminum titanate composite materials (CMAT), which, due to their phase assembly and microstructure, exhibit a strength advantage compared to aluminum titanate-feldspar composites and a volumetric heat capacity advantage compared to cordierite.
Diesel particulate filters (DPF) and gasoline particulate filters (GPF) can be obtained from a honeycomb porous ceramic by plugging neighboring channels in a checkerboard pattern on both ends to form a filter with inlet and outlet channels. The exhaust gas has to then flow through the wall of the honeycomb. During its path through the porous honeycomb wall, small particulates from the exhaust gas are deposited on the pore surface or on the soot layer at the wall surface, thus providing filtering of the exhaust gas. The forming soot cake is periodically burned in a regeneration cycle so that the DPF/GPF has a lifetime similar to that of the vehicle. Alternative filter designs can also be used, such as radial trough filters or radial disk filters, which compared to the honeycomb design with its long, narrow gas flow channels have wider gas flow channels and/or a stronger radial component for the gas flow, but share the same particulate filtering of the gas when it passes through the thin porous ceramic wall and offer the same opportunity for incorporation of a suitable catalyst in the wall-porosity and/or on the walls.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form any part of the prior art nor what the prior art may suggest to a person of ordinary skill in the art.